With the response:
RETS ReplyCode="20207" ReplyText="Unauthorized Query. You are not authorized access to the field [AO_board_id]."
RETS-STATUS ReplyCode="20207" ReplyText="Unauthorized Query. You are not authorized access to the field [AO_board_id]."
</rets>

Not specifying anything in the SELECT

Our login is upaor.rets.paragonrels.com/rets/fnisrets.aspx/UPAOR/login?rets-version=rets/1.5
and our user id is 'iHouse' for Upper Peninsula Association of Realtors